ATM Modernization, Business & GA, Commercial, Military

Avionics System Design: The Problem with Knowledge in the Head

By Walter Shawlee 2 | October 1, 1999
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Those of you who may have read Donald Norman’s The Psychology of Everyday Things (also released as The Design of Everyday Things) will understand the title of this month’s column perfectly. For those of you who haven’t read his books yet, don’t worry, I’ll explain—but get with it, go get a copy!

What led to this column were several horrifying demonstrations I was subjected to recently of "advanced" products (avionics and others) from manufacturers who clearly didn’t understand this concept at all. They convinced me that a refresher on this topic was overdue.

Norman’s books are outstanding both for their directness and their relevance to all phases of design and product creation. Probably better than any other modern designer, he was able to focus clearly on the exact issues that separate good from bad, workable from annoying, and safe from dangerous. He makes the distinction of such critical elements as "knowledge in the environment" and "knowledge in the head." These are areas where we all (including me) need constant reminders.

Knowledge in the head is that information that cannot be derived from an item’s examination and must be learned from some other source (often also not explained or obvious) in order to make it work. Many things fall into this category, from operating most fax machines and cell phones to using most avionics.

The user must spend considerable time and effort to puzzle out this information, and most importantly, remember it each time the device is used. This may sound trivial, but as the number of critical items the user must remember increases—each with their own illogical quirks—the higher the risk of improper operation.

This is not a big deal with your cell phone (unless you accidentally speed-dial some 900 phone-sex service at hellacious rates). But it can quickly be life threatening in the cockpit under high-stress situations.

Knowledge in the environment is intrinsic information that is clearly discernable by a device’s user, which prompts correct operation. This information may be in the form of labels, colors, messages, displays, shapes and possible selections, help functions, and so on, which guide any user at any skill level to do the right thing—and, ideally, only the right thing.

Just as J. Edwards Deming, who formulated quality control, correctly observed, the best manufacturing process is one that leads by default to correct assembly without selection, Norman observed that the best design is one that naturally leads the user to correct operation without resorting to outside, or divine, intervention.

This is by no means easy. If you look around at the things you use every day with an objective eye, you will soon discover an astounding array of items that are really a pain in neck to operate. It is an interesting development in our modern civilization: we have made our lives far more complex and frustrating but only rarely or accidentally better.

One chief complaint of people at all educational levels is that few things they have to use seem to work as intended or in the way they perceive as "correctly." The many VCRs all over the planet still flashing 12:00 a.m. or poorly utilized computers and software serve as testimony to this largely ignored problem.

I do not believe this is an issue of stupid, lazy or uneducated users. It’s stupid, lazy and uneducated designers.

You have to ask yourself what doofus decided that dozens of key commands like "shift-alternate-F7" would be easy and convenient for users to remember, why the heck you click on "Start" to shut off a Windows computer, or why on earth VCRs don’t have backup clock batteries. Needless to say, these phenomena are not confined to the world of consumer electronics.

I watched with fascination recently as an avionics salesman went through the operation of a new graphically based GPS/nav/com system. He tossed out many comments like "clearly," "just do this," and "easy to use" to three very intelligent (if you will allow me to visit this category at least temporarily for the purpose of this discussion) and experienced avionics people. The salesman finished with a smile and walked off to impress some other show attendees, while the three of us tried to get the unit to do anything. After 15 minutes, all we succeeded in doing was locking the system up in some mode we did not understand. We were never able to even channel the com side of the radio.

I left the booth amazed that anybody could take so much good technology and make it into such a user nightmare. It did look nice, though, which I’m sure was really important to the design and sales team.

The military has long understood that clarity is more critical than style, and they have often insisted on many more panel labels, consistency, prompts and user clues than are often seen in the civil world. They have also effectively counteracted this momentary "good force" with a brief visit to the "dark side," in which they translated even the simplest terms to needlessly cryptic abbreviations to stamp out any potential user awareness.

Civil designers also have fallen into the abbreviation trap and seem to take it as a "given" that no button or panel label is to be longer than three characters under pain of death. It’s almost as if all the panel letters in the universe are stored in a small locked room, run by a very stingy old codger, and you have to wheedle a few letters from him each time you want to mark something. In case anybody is wondering, users really do hate this nonsense.

During your next panel design, please remember that there are actually vowels in the English language. Feel free to use them.

With so many systems using a computer and complex display as their core, it remains an unexplained mystery why more do not provide some level of user guidance in the form of related screen prompts and messages. I think the pinnacle of this dark territory is probably ceded to various flight management and integrated nav systems. And if the problems flight crews regularly experience with this type of gear are any indication (remember "no fault found?"), it is a costly, frustrating, and safety-compromising design mis-step.

So, the point is a simple one: If somebody without super-powers and who didn’t actually design it, can’t operate it right out of the box, then more work is required before it’s ready for prime time. Everything is obvious to the guy that thought it up, it’s just too bad he won’t be buying them all, so the rest of us could get some other stuff that actually worked well.

I especially love the defensive response when asked to explain some truly unfathomable function—"Well, nobody has complained to me about that"—as if their personal phone number was taped on the front of every unit with instructions to immediately call in flight when something fails. Maybe that would fix this situation—but probably not. After all, nobody can actually figure out how to get through the voice mail system to reach him.

Products are not IQ tests that permit the specially informed to snicker at the hapless and floundering new users. If your customer doesn’t get it, that situation really says you don’t either. So, be nice to the user, never forget you will be one some day.

Walter Shawlee 2 welcomes reader comments and can be reached by e-mail at walter2@sphere.bc.ca

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